https://devzone.nordicsemi.com/f/nordic-q-a/60527/does-ble-retransmission-happen-in-same-connection-intervalHi All I am now developing BLE application on nRF52840 DK. I have a question about BLE retransmission process. When master sends a packet to initiate a connection event/interval, but due to interference, slave cannot receive it. Thus, there will noten-USTelligent Community 13Thu, 23 Apr 2020 11:35:24 GMThttps://devzone.nordicsemi.com/thread/246233?ContentTypeID=1Thu, 23 Apr 2020 11:35:24 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d2d9476e-a8ef-462f-aaad-3216e271f7c8Vidar Berg<p>The first packet at the start of a new connection event, or first data packet after a connection request (ie before the connection is established)? Anyway, the Window widening (section 4.5.7) accounts for clock drift and the master and slave should not drift apart that fast.&nbsp;</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/246201?ContentTypeID=1Thu, 23 Apr 2020 10:16:47 GMT137ad170-7792-4731-bb38-c0d22fbe4515:3497f7eb-6dc9-46cc-97c1-1aa92c300296BOZHENG<p>Hi, thanks for your answer.</p> <p>But if we consider about anchor point, the slave does not receive the first packet from master, it means the anchor point is not synchronized. How do master and slave decide the beginning of their next connection interval?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/246191?ContentTypeID=1Thu, 23 Apr 2020 09:42:52 GMT137ad170-7792-4731-bb38-c0d22fbe4515:8abe61cb-eb12-4776-b8cb-3d1b005ae6d8Vidar Berg<p>Hi,</p> <p>The master will attempt retransmission on the next connection event if the packet is not received by the slave. You may refer to&nbsp; Vol 6, Part B, section 4.5 of the BT core specification for more details.</p><div style="clear:both;"></div>